An Insider's Guide to Eclipse

There's never a dull moment for the Twilight cast, who headed to Vancouver Monday to begin pre-production for Eclipse, the third installment of Stephenie Meyer's hit vampire series.

Eclipse will have all of the tortured, mortal angst that Kristen Stewart's character, Bella Swan, goes through in Twilight and New Moon – but with more action, more blood, and yes, more Robert Pattinson.

The book picks up with Pattinson's character, Edward Cullen, and Bella reunited as a couple, while Jacob (Taylor Lautner) continues to vie for Bella's heart. But as Edward and Jacob compete for Bella's affections, the clans of vampires and werewolves unite over the common enemy: A set of murderous vampires (including the Volturi) who are on the hunt for Bella.

Here's what to expect on and off set in Vancouver as filming gets underway.

 New Faces on SetWith Rachelle Lefevre no longer portraying the blood-thirsty Victoria, Bryce Dallas Howard will step in to fill her role. Another new face is Australian actor Xavier Samuel, who plays a recruit in Victoria's army of vampires out for Bella's blood. Eclipse also provides meatier plotlines and more screen time for fan favorites Nikki Reed and Jackson Rathbone, who play Rosalie and Jasper Hale.

 Rob and Kristen Together While their characters get engaged in the movie, Pattinson and Stewart have been spending more time together off set as well. Starting Aug. 6 in Los Angeles, the pair spent two nights in a row together, attending concerts at the Hotel Café and then mingling with pals at the Chateau Marmont. Word on the movie set is that "[Michael] Angarano and Kristen Stewart are completely broken up," a source tells PEOPLE. "Everyone is pretty convinced that the Pattinson and Stewart are hooking up."

Taylor Lautner

 Fierce Fights! The vampires and werewolves are training for more intense fight scenes. "In Eclipse there is an epic battle," screenwriter Melissa Rosenberg told Entertainment Tonight. "With every book, with every episode of the movie, it gets grander in scale." The actors are planning accordingly: In Vancouver, they've begun fight training and getting in shape for the demanding roles. Peter Facinelli joked that to prepare, "I re-read Eclipse, I read the script. And then I got on a treadmill."

 Cast Bonding After arriving in Vancouver, Reed, Facinelli, Lautner, Howard, Rathbone, Kellan Lutz, Ashley Greene and producer Wyck Godfrey all convened over dinner in a private room at CinCin Restaurant on Robson Street. "It's really enjoyable," Greene says of hanging with the cast. "We can just be open and honest." Other favorite hangouts include the Glowball Grill, where Pattinson likes the spaghetti and meatballs, and the Yaletown Brewery, where the male cast members have gone for after-work drinks.

 Final Film?Eclipse is the last planned filmed adaptation of The Twilight Saga – for now. "I haven't heard anything about Breaking Dawn," Facinelli told Twilight Examiner on Aug. 3. "When we shot Twilight, no one knew if it was going to be a success or not, and we didn't know if we were going to shoot a second movie or not … If New Moon performs in the box office, and the fans come out, and Eclipse, then that's their way of saying they want more. I'm hoping when New Moon comes out they'll push the green button."